This invention relates to a novel aqueous insecticidal concentrate composition. The term "insecticidal concentrate composition" used herein is intended to mean a solution, such as an emulsifiable concentrate, which contains insecticidal compound preferably in a concentration as high as 2% or more and is practically-applied after dilution with water to a concentration of below 1%.
An aqueous pesticidal concentrate composition containing a triazine derivative, a pyridine derivative, a chlorinated hydrocarbon or others as a pesticidal compound is disclosed in British Pat. No. 1,446,771. However, the British Patent does not disclose an aqueous insecticidal concentrate composition containing an insecticidal organo-phosphorus compound as an active compound. An insecticidal organo-phosphorus compound in such known aqueous pesticidal concentrate composition in which the active compound is dispersed in water in the form of a finely divided solid is very unstable and decomposes with the lapse of time.
Accordingly, an aqueous insecticidal concentrate composition containing an insecticidal organo-phosphorus compound is unknown.
Known concentrate compositions containing an insecticidal organo-phosphorus compounds are generally composed of an insecticidal organo-phosphorus compound, an organic solvent, a surface active agent and a stabilizer. Water is scarcely contained in the compositions (e.g., the water content is generally below 1%). This is because organo-phosphorus compounds which serve as insecticide are usually poor in stability when water is present. Accordingly, it has been heretofore considered that the presence of water in the phosphorus compound-containing concentrate composition which is essentially required to have relatively long shelf life must be avoided.
Almost all of the organic solvents employed in the known concentrate compositions for agriculture or epidemic prevention, such as emulsifiable concentrates have more or less toxity against animals and plants and take part in air or water pollution leading to many evils when used as insecticides. Further, the organic solvents employed in conventional insecticidal concentrate compositions are ordinarily combustible and have a danger of taking fire, so that the insecticidal concentrate compositions using such combustible organic solvents and containing no water must be handled or stored with the utmost care. Accordingly, use of water instead of organic solvents is very convenient from every point of view. In addition, organic solvents which have been used in insecticides are important as starting materials for the synthesis of useful compounds or energy sources. In the sense, the replacement of organic solvents by water is favorable from a social point of view.